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Calibration
8.3
Messages during adjustment
The following messages may appear on the display during
zero adjustment and span adjustment.
Display
Description
sequence
Lower adjustment
limit exceeded.
Upper adjustment
limit exceeded.
Gas concentration
HI - GAS
exceeds sensor
range during
adjustment
LO - GAS Gas concentration
is too low for cor-
rect adjustment
PLS -
Validity of the zero
adjustment has
CAL-
ZERO
expired.
The maximum time
between valid zero
adjustment and
span adjustment is
24 hours.
8.4
Test gases
Please refer to the instructions for use provided for the
respective sensor for the test gas properties (e.g. relative
humidity, concentration). If there is no information provided
relating to relative humidity, dry test gas can be used for the
adjustment. The humidity of the test gas is not relevant for O
sensors.
Depending on the type of adjustment, various types of test
gas are used.
Zero gas
The zero gas is a test gas used for adjustment of the zero-
point of a sensor. Nitrogen (N
sensors. With other sensors, ambient air can be used once it
is free from disruptive contamination and the measured gas.
Target gas
The target gas is a test gas that is used for adjusting the
sensitivity of a sensor. The target gas is a known
concentration of the measured gas, diluted with clean air and
nitrogen. Target gas is not required for O
from the ambient air is used.
8.5
Gas flow for adjustments
The gas flow varies according to each sensor.
EC sensor, CAT sensor
All other sensors
16
Action
Tap the [DOWN] button
Tap the [UP] button
Use a lower test gas con-
centration or tap the
[DOWN] button
Use a higher test gas con-
centration or tap the [UP]
button
Perform zero adjustment
) is used for O
and CO
2
2
2
sensors, as oxygen
2
0.5 L/min ± 10 %
0.5 L/min - 2 L/min
The gas flow rate for adjustment should be the same as the
flow rate or pump capacity during operation. To calculate the
gas flow (volume flow), the cross-section of the pipe or duct is
required (volume flow = pipe cross-sectional area x flow rate).
8.6
Preparing for adjustment
General information
WARNING
Health hazard due to test gas
Inhaling test gas may risk health or lead to death.
► Do not inhale test gas.
► Observe risks and security statements related to the test
gas (Refer to data sheets and instructions figuring on
calibration devices).
CAUTION
Triggering alerts by test gas
Applied test gas may trigger alerts.
► Make sure that test gas is no longer applied after
calibration.
Prerequisites
– The sensor warm-up phase has been completed (see
"Commissioning", page 13).
Special feature of the Polytron 5310
Dräger recommends carrying out an automatic zero
calibration on the sensor before adjustment of the zero-point.
This resets the zero-point tracking of the DrägerSensor IR,
and the full tracking range is available.
1. Use the calibration adapter to apply nitrogen, synthetic air,
or clean air to the sensor and wait until a stable measured
value is shown.
2. Set the magnetic wand on the area marked with the
2
symbol (inside of the black border) on the surface of the
sensor shell and hold it in place for at least 5 seconds.
After 5 seconds, the sensor output signal switches to the
display of the calibration signal (display change by approx.
–10 %LEL) for as long as the magnetic wand is held in
place. At the same time, a zero calibration of the optical
measurement system is automatically performed.
3. Remove the magnetic wand. After 30 seconds, the
instrument exits the automatic zero calibration routine. To
confirm the automatic zero calibration, the output signal
switches back to the calibration signal (display change to
approx. –10 %LEL). This signal is also displayed for the
same length of time as when starting the automatic zero
calibration routine.
Polytron 5100, Polytron 5200, Polytron 5310
See figure B on the fold-out page.
Adjustment equipment:
– Dräger pressure regulator (1), use a stainless steel
pressure regulator for reactive gases
– Dräger calibration adapter (2) (part number 6810536)
– Hose (3)
– Dräger test gas cylinder (4)
Instructions for use
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Dräger Polytron 5000 Series
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